J. M. Ordway on Waterglass. 33 
Bisilicate of Soda,—with Alcohol of sp. gr. 0°840. 
25.—100 pts. of a solution containing 1 p.c. of Nato Sisu,—with 50 of 
alcohol ereare a slight, insoluble, ib iadeeg fee precipitate coctitning 
Nanoo Sis 
26.—100 pts. of a solution containing 1:9 f Nato Sizis,—with 40 
of alcohol,—gave 1:1 pts. of a hard ‘eclbitite containing earthy 
matters and Naiw Biss. Out of this boiling water dissolved nearly all 
the soda and one fourth of the silica. 
27.—100 pts. of a solution containing 3°45 of Naroo Sigua,—wit th 40 
of aleohol,—gave 4°6 pe of a hard sen peat; soluble in cold water, 
and containing 51 p. ¢. of Naoo Siasz. 
28.—100 pts. of a sol aie containing 34°5 p. c. of Naws Sizu,—with 40 
of alcohol,—-gave 63°5 pts. of a hard precipitate containing 52 p. c. of 
Nao Siarz. 
Ferruginous Silicate of Soda,—with Alcohol of sp. gr. 0°824. 
29,a.—Into 40 pts. of a solution containing 23°5 ie c. of Naioo Sites 
atireed 60 = of : solution containing 1*1 p. ¢ of dry protoslphnt 
of iron. e protoxyd of iron was almost entirely taken up. 
filtered liquor was ay SP transparent and of a very deep blue biack 
98 pts. “of this filtrate——with 10 of alcohol,—gave 4°7 pts. of a 
gray previpliste containing, besides the silicate of the mother liquor 
soaked up, 4 Ld p- ¢ of tes Nas Sis. 
b.—80 pts. of i colorless supernatant liquor of a,—with 11 of alcohol, 
Ree 7 pts. of a soft, soluble precipitate containing 45 p. ¢. of Nanoo 
~ —84 pts. of a supernatant liquor of b,—with 21 of aleohol,—gave 3°5 
pts. of a very soft precipitate free from i iron, and containing 47 p. c. of 
Naioo i173. 
In investigating the nature of alkaline silicates for is, for some 
purposes especially important to eliminate the last traces of for- 
eign matters. For instance, a vere article which is already 
mer says:—“ Silicate of potash in w 
ner times at op of nite base, is still soluble; ‘ 
the slightest additional quantity of _ is no longer ¢ dissolved.” 
They both evidently overlooked t 
nifnnate portions of earthy matter. Tor in reality, by operating 
* Op. supra cit.—p. 15, + Poggendorff’s Annalen,—: , p. 341. 
Au. Jour. Sct—Szconp Series, Vou. XXXII, No. 97.—Jax., 1862. 
